Typically, a system that is powered by a programmable power supply communicates power control feedback signals using an I2C or similar digital data interface, which requires two-pin signaling. For devices that have only a small number of total pins, it may not be desirable or practical to dedicate two pins for power control signaling. In such cases, it would be useful to limit power control signaling to only a single pin. Moreover, if a single line power control feedback signal or a signal derived from the power control feedback signal is used to drive a single input pin (e.g., reference voltage) of a power supply, it is possible to make even a non-programmable supply programmable.
Thus, there is a need for an improved way to communicate a power control feedback signal.